Cellular analysis of bronchoalveolar lavage fluid to narrow differential diagnosis of checkpoint inhibitor-related pneumonitis in metastatic melanoma

TIGIT Regulates T Cell Inflammation in Airway Inflammatory Diseases

TIGIT, a co-inhibitory receptor found on T cells and NK cells, transmits inhibitory signals upon binding to its ligand. This interaction suppresses the activation of various signaling pathways, leading to functional exhaustion of cells, ultimately dampening excessive inflammatory responses or facilitating immune evasion in tumors. Dysregulated TIGIT expression has been noted in T cells across different inflammatory conditions, exhibiting varying effects based on T cell subsets. TIGIT predominantly restrains the effector function of pro-inflammatory T cells, upholds the suppressive function of regulatory T cells, and influences Tfh maturation. Mechanistically, the IL27-induced transcription factors c-Maf and Blimp-1 are believed to be key regulators of TIGIT expression in T cells. Notably, TIGIT expression in T cells is implicated in lung diseases, particularly airway inflammatory conditions such as lung cancer, obstructive pulmonary disease, interstitial lung disease, sarcoidosis, and COVID-19. This review emphasizes the significance of TIGIT in the context of T cell immunity and airway inflammatory diseases.

Immune checkpoint inhibitor-related pneumonitis: research advances in prediction and management

The advent of immune-checkpoint inhibitors (ICIs) has revolutionized the treatment of malignant solid tumors in the last decade, producing lasting benefits in a subset of patients. However, unattended excessive immune responses may lead to immune-related adverse events (irAEs). IrAEs can manifest in different organs within the body, with pulmonary toxicity commonly referred to as immune checkpoint inhibitor-related pneumonitis (CIP). The CIP incidence remains high and is anticipated to rise further as the therapeutic indications for ICIs expand to encompass a wider range of malignancies. The diagnosis and treatment of CIP is difficult due to the large individual differences in its pathogenesis and severity, and severe CIP often leads to a poor prognosis for patients. This review summarizes the current state of clinical research on the incidence, risk factors, predictive biomarkers, diagnosis, and treatment for CIP, and we address future directions for the prevention and accurate prediction of CIP.

Effects of immune-related adverse events (irAEs) and their treatment on antitumor immune responses

Immune checkpoint inhibitors (ICIs) are potentially life-saving cancer therapies that can trigger immune-related adverse events (irAEs). irAEs can impact any organ and range in their presentation from mild side effects to life-threatening complications. The relationship between irAEs and antitumor immune responses is nuanced and may depend on the irAE organ, the tumor histology, and the patient. While some irAEs likely represent an immune response against antigens shared between tumor cells and healthy tissues, other irAEs may be entirely unrelated to antitumor immune responses. Clinical observations suggest that low-grade irAEs have a positive association with responses to ICIs, but the correlation between severe irAEs and clinical benefit is less clear. Currently, severe irAEs are typically treated by interrupting or permanently discontinuing ICI treatment and administering empirically selected systemic immunosuppressive agents. However, these interventions could potentially diminish the antitumor effects of ICIs. Efforts to understand the mechanistic relationship between irAEs and the tumor microenvironment have yielded meaningful insights and nominated therapeutic targets for irAE management that may preserve or even boost ICI efficacy. We explore the clinical and molecular relationship between irAEs and antitumor immunity as well as the role that irAE treatments may play in shaping antitumor immune responses.

Characterization of immunomodulatory factors and cells in bronchoalveolar lavage fluid for immune checkpoint inhibitor-related pneumonitis

As immune checkpoint inhibitors (ICIs) are widely used, a series of immune-related adverse events (irAEs) have been reported, including immune checkpoint inhibitor-related pneumonitis (ICI-pneumonitis). The incidence of ICI-pneumonitis is higher in reality than in clinical trials. The diagnosis is challenging, mainly based on clinical and imaging features, and requires the exclusion of other causes. The data on the biological mechanisms of ICI-pneumonitis are scarce, resulting in little knowledge of the best treatment for ICI-pneumonitis. Bronchoalveolar lavage (BAL) may be helpful to identify the biological differences or find predictive biomarkers, and may in turn help to develop phenotype-specific targeted drugs to treat ICI-pneumonitis. Herein, we outline the characterization of immunomodulatory factors and cells in bronchoalveolar lavage fluid for ICI-pneumonitis. Through careful sorting and literature review, we find crosstalk between pathogenic Th17/Th1 cells (i.e., Th17.1) and pro-inflammatory monocytes, and activation of Th17(/Th1)/IL-17A (/IFN-γ) pathways may play a key role in the pathogenesis of ICI-pneumonitis. Disruption of the interaction between pathogenic Th17/Th1 cells and pro-inflammatory monocytes (such as, anti-IL-23) may be a potential treatment for ICI-pneumonitis. We first describe the possible pathophysiological mechanisms of ICI-pneumonitis, hoping to contribute to the optimization of diagnosis and treatment, as well as provide readers with research inspiration.

Nintedanib in an elderly non-small-cell lung cancer patient with severe steroid-refractory checkpoint inhibitor-related pneumonitis: A case report and literature review

Immune checkpoint inhibitors tremendously improve cancer prognosis; however, severe-grade immune-related adverse events may cause premature death. Current recommendations for checkpoint inhibitor-related pneumonitis (CIP) treatment are mainly about immunosuppressive therapy, and anti-fibrotic agents are also needed, especially for patients with poor response to corticosteroids and a longer pneumonitis course. This is because fibrotic changes play an important role in the pathological evolution of CIP. Here, we report a case demonstrating that nintedanib is a promising candidate drug for CIP management or prevention, as it has potent anti-fibrotic efficacy and a safety profile. Moreover, nintedanib could partially inhibit tumor growth in patients with non-small-cell lung cancer, and its efficacy can be improved in combination with other anti-tumor therapies.

Immune checkpoint inhibitor-related pneumonitis and COVID-19: a case-matched comparison of CT findings

OBJECTIVES

To compare the radiological findings of immune checkpoint inhibitor-related pneumonitis (IRP) and COVID-19 pneumonia, evaluating the potential of the CO-RADS score to differentiate between them.

METHODS

Two readers blindly reviewed chest CTs from age- and sex-matched groups of 33 patients with IRP and 33 patients with COVID-19 pneumonia. Each examiner evaluated the presence of 13 CT features, semiquantitatively scored lung involvement, and assigned a CO-RADS score. Inter-reader reliability in the assessment of CT features and CO-RADS categories was evaluated with Cohen's κ. Distribution differences between groups were evaluated with the χ², Fisher's, and Mann-Whitney U tests.

RESULTS

Substantial or higher inter-reader reliability was found in CO-RADS assignments (κ = 0.664) and in the evaluation of CT features (κ ≥ 0.638), among which the sole feature found to significantly differentiate IRP from COVID-19 pneumonia was unilateral presentation (p < 0.001). Lung involvement semiquantitative scores and CO-RADS scores were significantly higher (p < 0.001) in COVID patients (median involvement score 4, IQR 4-6; median CO-RADS score 5, IQR 4-5) than in IRP patients (median involvement score 2.5, IQR 2-4; median CO-RADS score 3, IQR 3-4) but exploratory analysis of CO-RADS specificity revealed comparatively low values, ranging between 51.5% (Reader 1) and 54.6% (Reader 2).

CONCLUSIONS

CT features of IRP and COVID-19 pneumonia frequently overlap, save for the extent of lung involvement and bilaterality. In the current SARS-CoV-2 pandemic, the low specificity of the CO-RADS score for the differential diagnosis of COVID-19 pneumonia and IRP may prompt to reconsider the role of imaging in IRP work-up.

Immune-related pulmonary toxicities of checkpoint inhibitors in non-small cell lung cancer: Diagnosis, mechanism, and treatment strategies

Immune checkpoint inhibitors (ICI) therapy based on programmed cell death-1 (PD-1) and programmed cell death ligand 1 (PD-L1) has changed the treatment paradigm of advanced non-small cell lung cancer (NSCLC) and improved the survival expectancy of patients. However, it also leads to immune-related adverse events (iRAEs), which result in multiple organ damage. Among them, the most common one with the highest mortality in NSCLC patients treated with ICI is checkpoint inhibitor pneumonitis (CIP). The respiratory signs of CIP are highly coincident and overlap with those in primary lung cancer, which causes difficulties in detecting, diagnosing, managing, and treating. In clinical management, patients with serious CIP should receive immunosuppressive treatment and even discontinue immunotherapy, which impairs the clinical benefits of ICIs and potentially results in tumor recrudesce. Therefore, accurate diagnosis, detailedly dissecting the pathogenesis, and developing reasonable treatment strategies for CIP are essential to prolong patient survival and expand the application of ICI. Herein, we first summarized the diagnosis strategies of CIP in NSCLC, including the classical radiology examination and the rising serological test, pathology test, and artificial intelligence aids. Then, we dissected the potential pathogenic mechanisms of CIP, including disordered T cell subsets, the increase of autoantibodies, cross-antigens reactivity, and the potential role of other immune cells. Moreover, we explored therapeutic approaches beyond first-line steroid therapy and future direction based on targeted signaling pathways. Finally, we discussed the current impediments, future trends, and challenges in fighting ICI-related pneumonitis.

Diagnostic and therapeutic approach to pulmonary infiltrates in cancer patients receiving immune checkpoint inhibitors

The advent of immune checkpoint inhibitors (ICIs) targeting cytotoxic T lymphocyte antigen 4 (CTLA-4) and the programmed cell death (PD-1)/PD-1 ligand 1 (PD-L1) axis has transformed the treatment paradigm for multiple cancer types. ICIs are able to restore T-cell-mediated antitumor responses and do not entail an increased risk of infection per se. However, immunotherapy is associated to a unique form of toxicity due to the off-target effects on healthy tissues of the excessively enhanced immune response in form of immune-related adverse events (irAEs). Although ICI-induced pneumonitis ranks the fifth of all irAEs in terms of frequency of occurrence, it is associated with a relevant attributable mortality. This review summarizes the incidence, risk factors, clinical and radiological presentation, and therapeutic approach of ICI-induced pneumonitis. Particular focus is on the differential diagnosis of new or worsening pulmonary infiltrates in cancer patients receiving ICI therapy. Finally, the impact on the risk of opportunistic infection of ICIs and immunosuppressive therapy used to treat associated irAEs is reviewed. The diagnosis and management of suspected ICI-induced pneumonitis remains clinically challenging Current management of CMV infection in cancer patients (solid tumors). Epidemiology and therapeutic strategies.

Immune checkpoint inhibitor-related pneumonitis in non-small cell lung cancer: A review

Immune checkpoint inhibitors (ICIs) have shown definite therapeutic effects in various types of cancers, especially non-small cell lung cancer (NSCLC). However, ICIs have unique side effects, called immune-related adverse events (irAEs), which can occur in various systems throughout the body. Among such irAEs, immune checkpoint inhibitor-related pneumonitis (ICI-P) is a fatal adverse reaction. In this review, we discussed the risk factors, pathogenesis, clinical characteristics, radiological manifestations, pathological features, diagnosis, grading, and management of ICI-P in NSCLC and the relationship between ICI-P and the efficacy of ICI therapy. In addition, we discussed the predictive factors for ICI-P. This review will play a crucial role in the prediction, evaluation, and management of ICI-P for widespread application of immunotherapy.

A potential mechanism of the onset of immune-related pneumonitis triggered by anti-PD-1 treatment in a patient with advanced adenocarcinoma lung cancer: case report

Background

In recent years, the application of immunotherapy combined with chemotherapy in the first-line lung cancer has showed significant benefit in improving long-term survival. Immunotherapy also has risks of immune-related pneumonitis (IRP) after long-term treatment. Despite the treatment strategy of the IRP has been very clear. However, the mechanism is unclear.

Case presentation

A 73-year-old male patient was diagnosed with left lung adenocarcinoma IVa, EGFR, ALK, ROS1 negative. The patient received anti-PD1 antibody combined with pemetrexed and cisplatin. After 5 cycles of treatment, partial response was obtained. Subsequently, the patient continued the treatment of anti-PD1 antibody combined with pemetrexed. Before the 7th cycle, the CT found a new lesion in the basal segment of the right lower lobe. It was diagnosed with IRP and pneumocystis jirovecii. The patient did not give trimethoprim–sulphamethoxazole (TMP–SMX) and corticosteroids, symptoms and radiological lesions had improved. We describe the report of immune-related pneumonitis trigged by anti PD-1 and monitored the dynamic changes of CD⁴⁺, CD⁸⁺ T lymphocytes, MDSC and Treg cells in the bilateral bronchoalveolar alveolar lavage fluid. From the point of view of immune cells, the mechanism of immune reconstitution inflammatory syndrome is confirmed. Based on the current case report and literature, this study proposes a potential mechanism of the onset.

Conclusion

Immune reconstitution inflammatory syndrome may be potential mechanism of IRP. This study may improve our understanding of the pathogenesis underlying IRP. We believe the detection and dynamic monitoring CD4⁺, CD8⁺ T lymphocytes, MDSC and Treg cells can provide more accurate procedures.